Godan verb with 'su' endingintransitive verb to lie down (in bed);to retire (to bed);to become bedridden (with an illness)

su verb - precursor to the modern suruintransitive verb archaic to lie down (in bed);to take to one's bed

intransitive verb archaic honorific or respectful (sonkeigo) language to lie down

suru verb - special classintransitive verb rare term to lie down (in bed);to take to one's bed